Apparatus for the heat treatment of materials



Dec. 7 1926. 1,610,078

A D. DUCKHAM APPARATUS FOR THE HEAT TREATMENT OF MATERIALS I Filed Jan. 17, 92 4 2 Sheets-S heet 1 yen 2 a) driiar/l jalz yallfiaazim Dec. 7 1926.

A. M D. DUCKHAM APPARATUS FOR THE HEAT TREATMENT OF MATERIALS Filed Jan. 17, 1924 2 Sheets-Sheet Patented Dec. 7, 1926.

UNITED "STATES PATENT OFFICE.

ARTHUR. Me oUGALL DUGKHAM, OF LONDON, ENGLAND, ASSIGNOR TO THERMAL IN- DUSTRIAL & CHEMICAL (r. I. C.) RESEARCH COMPANY LIMITED, or LoND'oN, ENG- LAND.

. APPARATUS FOR THE HEATTBEATMENT OF MATERIALS.

I Application filed January 17, 1924. Serial No. 686.876. and in Great Britain February 2. 1 923.

immersed in molten metal, and a device for causin relative rotary movement between the spiral blade and the molten metal.

The invention is particularly applicable to molten metal baths for distillation of tar,

oil or the like, such as are described in Unit ed States Patent No. 1,527,847.

It has been found that in working apparatus of this class, when the liquid residues of distillation or heat treatment travel over the surface of the moltenmetal, difiicultie's, are encountered owin'g'to the fact that free,

carbon, ash,.or other finely-divided solid material has a tendency to settle on the surface of the metal, oyei which the liquid products .travel, forming a solid layer and thereby re I ducing the efliciency of heat transmission between the metal and the liquid products.

It is an object of the present invention to obviate these difiiculties by the removal of the free carbon, ash or other finely divided material. For this purpose a spiral blade of the kind referred to is slowly revolved on a vertical axis within a cylindrical still during the distillation of the tar, oil or the like which preferably enters the still axially; or the blade may be stationary and the lead .may be caused to revolve by a paddle revolving beneath its surface.

In one arrangement the lower edge of the blade dips below the surface of the metal and cleanses the surface of any deposit of carbonaceous or other solid material from the centre to the periphery of the still and at the same time causes a positive travel of the liquid products over the surface of the metal. An outlet is provided on the periphcry of the still from which the carbonaceous or other solid material is ejected by the spiral rotating blade. One effect of the submersion of the lower ed e of the blade in the molten metal is to pr uce a certain degree of agitation of the metal. In addition to removing matter from the surface of the liquid, and producing a positive travel of material over the surface from the inlet towards the outlet, the partly submerged blade acts as a baffle. and causcsthe materialto'l'raverse an extended path, and so to remain in contact with the molten metal for such time as may be necessary for the completion of the heat treatment.

The accompanying drawing shows in vertical section in Fig. l and in plan in Fig. 2, a still for distilling tar with aid of molten lead, provided with a spiral blade in accordance with the invention.

Fig. 3 is a vertical section of a modification and Fig. 4 is a plan of Fig.3, the cover having been removed. I

The still a contains molten lead I) and-has a cover 0.

Referring to Figs. 1 and 2, through the centre of the cover extends a tube d'having a solid end-e 'supportedon the bottom of the still. The tube carries a hood 7 of the kind described in United States Patent No; 1,527,847 communication between the hood and the tube is through perforations g in the latter. The tar to be distilled is forced through the tube into the hood and passes through the serrations of the lower edge of the latter to rise on to the surface of the molten lead. The upper part of thehood forms a bearing surface for a hollow shaft h co-axial with the tube d and driven by a worm wheel 5' and a worm not shown; a tight joint between the tube d and the shaft is afforded by a stufiing box k, and between the shaft and the cover a by a stufling box Z.

The lower part of the shaft carries a hub m to which are bolted arms n carrying the spiral blade 0, this construction being strengthened by ties 19 between the farend of two of the arms n and a collar 9 on the shaft.

The rotation of the blade 0 forces matter that floats on the molten lead to a discharge opening 1' in the side of the still.

s is a tube for receivin t is the connection of t e still with a condenser. I

Referring to Figs. 3 and4, the spiral blade 0 is fixed at one end to the annular hood 7.

The tar is fed into the annulus of the hood through pipe at. Thus the blade remains stationary and in order to produce the movement necessary for causing the material on the surface of the molten lead to travel to the discharge opening a", there is provided an axial shaft 0 driven by worm w and cara thermometer and rying at its lower end the addle w. The

revolution of the paddle in t e metal causes the latter to revolve.

Having thus described the nature of the said invention and the best means I knowv for carrying the same into practical effect, I claim 1. Apparatus for the heat treatment of materials by travel over the surface of molten metal, comprising a chamber contaimng molten metal and having in close proximity to and above the surface of the molten metal an outlet for treated material, means for feeding material to the surface of the molten metal, a baflie which is spiral in plan, means supporting the battle in a position adapted for guiding to the outlet material fed to the surface of the molten metal, and with its lower edge immersed in the molten metal,

and means for causin relative rotary movement between the b e and the molten metal.

2. Apparatus for the heat treatment of materials by travel over the surface. of molten metal, comprising a chamber containing molten metal and having in close roximity to and above the surface of the mo ten metal.

and means for causing the bafile to rotate about a vertical axis;

In testimony whereof I have signed my name to this specification. ARTHUR MCDOUGALL DUCKHAM. 

